Gori Alessandra, Leone Fabrizio, Loffredo Lorenzo, Cinicola Bianca Laura, Brindisi Giulia, De Castro Giovanna, Spalice Alberto, Duse Marzia, Zicari Anna Maria
Department of Pediatrics, Sapienza University, Rome, Italy.
Department of Internal Medicine and Medical Specialties, Sapienza University, Rome, Italy.
Front Neurol. 2020 Sep 10;11:956. doi: 10.3389/fneur.2020.00956. eCollection 2020.
Anosmia is a well-described symptom of Corona Virus Disease 2019 (COVID-19). Several respiratory viruses are able to cause post-viral olfactory dysfunction, suggesting a sensorineural damage. Since the olfactory bulb is considered an immunological organ contributing to prevent the invasion of viruses, it could have a role in host defense. The inflammatory products locally released in COVID-19, leading to a local damage and causing olfactory loss, simultaneously may interfere with the viral spread into the central nervous system. In this context, olfactory receptors could play a role as an alternative way of SARS-CoV-2 entry into cells locally, in the central nervous system, and systemically. Differences in olfactory bulb due to sex and age may contribute to clarify the different susceptibility to infection and understand the role of age in transmission and disease severity. Finally, evaluation of the degree of functional impairment (grading), central/peripheral anosmia (localization), and the temporal course (evolution) may be useful tools to counteract COVID-19.
嗅觉丧失是2019冠状病毒病（COVID-19）的一种广为人知的症状。几种呼吸道病毒能够导致病毒感染后嗅觉功能障碍，提示存在感觉神经性损伤。由于嗅球被认为是一个有助于防止病毒入侵的免疫器官，它可能在宿主防御中发挥作用。COVID-19局部释放的炎症产物导致局部损伤并引起嗅觉丧失，同时可能会干扰病毒向中枢神经系统的传播。在这种情况下，嗅觉受体可能作为严重急性呼吸综合征冠状病毒2（SARS-CoV-2）局部、在中枢神经系统及全身进入细胞的另一种途径发挥作用。因性别和年龄导致的嗅球差异可能有助于阐明对感染的不同易感性，并理解年龄在传播和疾病严重程度中的作用。最后，评估功能损害程度（分级）、中枢性/外周性嗅觉丧失（定位）以及时间进程（演变）可能是对抗COVID-19的有用工具。
